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J. G. CLEMENS.

REFILLABLE FUSE PLUG.

APPLICATiON FILED JULY 9 1919.

1,848, 39 1 Patented Aug. 3, 1920.

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UNITED STATES PATENT OFFICE.

JOHN G. CLEMENS, OF BUFFALO, NEW YORK, ASSIGNOR T0 CLEMENS ELECTRICAL CORPORATION, OF BUFFALO, NEW YORK, A CORPORATION OF NEW YORK.

REFILLAIBLE FUSE-PLUG.

Specification of Letters Patent.

Patented Aug. s, 1920.

Application filed July 9, 1919. Serial No. 309,606.

To all whom it may concern Be it known that I JOHN G. GLnMnNs, a citizen of the United tates, residing at Buffalo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Refillable Fuse-Plugs of which the following is a specification.

This invention relates to refillable fuse plugs. v

One object of the present invention is to provide a fuse plug so constructed as to permit of escape of the gases generated when the fuse is blown and to at the same time provide for cooling of these gases so that there will be no likelihood of flame being discharged from the plug.

Another object of the invention is to so construct the plug that no gases will be permitted to escape from theplug at the point of'location of the plug contact located at the inner end of the said plug.

Another object of the invention is to pro vide a refillable fuse plug so constructed that the fusible element thereof will not be liable to be distorted after having been placed within the plug and while assembling the sections of the plug.

Another object of the invention is to provide a fuse plug with a novel and highly effective arrangement of vents for the gases generated when the fuse is blown.

In general the invention has as its object to provide a fuse plug which 'will blow without noise and without the discharge of flame or hot gases to its exterior; the parts of which may be readily disassembled and reassembled to provide for renewal of the fusible element of the plug; and, which plug may be readily manufactured at a low cost.

In the accompanying drawings:

Figure 1 is a perspective view of the fuse plug embodying the present invention;

Fig. 2 is a vertical longitudinal sectional view therethrough;

Fig. 3 is a perspective view of the body of the plug; I

Fig. 4; is a group perspective view illustrating the several parts comprising the renewable fusible element of the plug.

In the drawings'the body of the fuse plug is indicated in general by the numeral 1 and the said body is preferably formed from porcelain or other suitable insulating material and is substantially of the shape of a hollow cylinder closed at one end as indition of a wrench for the purpose stated.

Alsothis end of the body is formed with an opening 7 located preferably axially of the said end.

The shell of the plug is indicated in general by the numeral 8 and the said shell is as usual of brass or other metal suitable for the purpose and having its wall crimped to provide threads 9 to fit the threads 5 of the body 1 and to also fit the threads of the fuse plug socket. The shell 8 is, of course, open 'at one end to receive the body 1 of the plug and at its other end it is closed, as indicated by the numeral 10,-rivets orother suitable fastening devices 11 being secured through this end of the shell and through the end of a cap 12 of insulating material. The cap 12 fits over the closed end of the shell 8 and being of insulating material maybe grasped for the purpose of fitting the plug into the socket and removing the same therefrom. For a purpose to be presently explained a Washer 13 of asbestos or other fireproof material sufficiently yieldable to constitute a packing, is disposed within the closed end of the shell 8 and is designed to be engaged by the open end of the bodyl of the plug when the body is fitted into the shell.

I will now describe the renewable fusible element of the plug and will then describe the manner in which it is to be assembled with the body and shell of the plug.

The parts comprising the renewable fusible element are clearly shown assembled in F 1g. 2 of the drawings and disassembled in Fig. 4, the said element being indicated in general by the numeral 1d. The element proper is formed from a strip or ribbon of sheet metal, indicated by the numeral 15 and of the required dimensions to offer a preand thence upwardly to provide a tongue 19 extending beside the adjacent portion of the body oft-he fusible element. in this manner the element is provided at one end with a head 20. Assembled with this head is a clip, indicated in general by the numeral 21, and comprising spaced tongues 22 and a transverse head 23 formed in the same manner as the head 20 but somewhat of open construction as indicat d by the numeral 2% so as to fit over and inclose the head 20 with one of the tongues extending upwardly beside the outer face of the tongue 19 and the other tongue extending upwardly beside the outer face of the said adjacent portion of the body of the fusible element 1%. The numeral 25 indicates in gene 'al a contact head which maybe of brass or other suitable metal or composition of metals and which normally has an upstanding rim shown in dotted lines in Fig. l of the drawings, this rim being designed to be crimped in as indicated by the numeral 26 after the heads 20 and of the fusible element and the clip 21 have been disposed within the said contact head so as to secure the contact element and its clip in assembled relation and also to secure the contact head to these assembled parts. T he numeral 27 indicates a washer which of rubber or other suitable compressible material and this washer is provided with an opening 28 to permit of the passage therethrough of the body of the fusible element i-l and the tongues 22 of the clip 21 as clearly shown in Fig. 2 of the drawings.

In assembling the fusible element with the body of the plug, the strip 15 in straight or unbent form is first inserted through the opening 7 in the direction of the interior of the body 1, the tongues 19 and 22 being finally passed through this opening until the washer 2T bears against the outer end of the polygonal head 6, and the contact head 25 bears against the washer. The terminal portions of the tongues 19 and 22 are then turned downwardly in opposite directions, as clearly shown in Fig. 2 of the drawings, so as to bind against the inner face of the closed end wall 2 of the body 7 of the plug, and the fusible element is in this manner securely anchored in place at one end. In order to insure of perfect electrical contact between the fusible element 1% and its clip 21 and to hold these parts together after they have been assembled in the factory, it is preferable that the terminal portion of the tongue 19 be soldered, as indicated by the numeral 29, to the terminal portion of the corresponding one of the tongues 22, as clearly shown in Fig. 2 of the drawings.

The strip 15 of the fusible element is flexible and after it has been anchored at one end in the closed end of the body 1 as above described, it is bent over the wall of the said body at the open end of the body, as indicated by the numeral 30 and to seat in a notch 31 formed in the said end of the wall .of the body. Exteriorly the body is formed with a longitudinally extending groove or channel leading from this notch toward the closed end of the body and terminating preferably at the innermost one of the threads 5, this channel being of a width and depth to receive the free end portion of the said strip 15, as clearly shown in Fig. 2 of the drawings,-and the terminal of the said end portionbeing crimped as at 33 to seat between the threads 5 of the body 1 and the threads 9 of the shell 8. Thus the body may be threaded into the shell and the terminal of the strip 15 securely anchored in place and in electrical contact with the shell 8 without any likelihood of the strip being distorted inasmuch as its engagement in the groove or channel 32 prevents any sidewise motion of the end portion so engaged.

In order to localize the fusing of the element ll, the said element is preferably cutaway at an intermediate point in its portion between its bend 30 and its end which is anchored at the closed end of the body 1, as indicated by the numeral This narrowed portion of the strip comprising the fusible element proper will therefore be located substantially centrally within the chamber 3 of the body of the plug and upon blowing of the fuse practically this portion alone of the said element will be fused and will melt.

From the foregoing description it will be understood that when the plug is blown it is only necessary, in order to refill the same, to separate the body from the shell, pull out the fusible element by gripping and pulling upon the contact head 25, insert a new element into place through the opening 7 and forming the bend 30, and then reassemble the body and shell.

When the plug is fitted into its socket, the contact head 25 will be caused to bear firmly against the contact or terminal at the inner end of the socket and consequently will be pressed in the direction of the outer end of the polygonal head 6 of the body 1 with the result that the washer 27 will be compressed between the said end of the head 6 and the rim of the contact head 25 and thus gases generated through fusion of the fusible element will not be permitted to escape through the opening 7. r

In order, however, that the gases may be permitted to escape after they have sufficiently cooled to eliminate likelihood of fire or the issuance with them of flame, the wall of the body 1 of the plug at its open end is formed with a plurality of notches 35 and the body is formed with longitudinally extending vent passages 36 extending through the threads 5 of the said body. Thus the gases generated through fusion of the elemeat 14 must first pass relatively slowly through the slits or notches 35, then between the wall of the body 1 and the wall of the shell 8, and finally relatively slowly outwardly through the vent passages 36 to the atmosphere.

From the foregoing description of the invention it will be seen that have provided a fuse plug which may be readily and con veniently refilled after it has been blown and the blowing of which will not be accompanied by the discharge of flame or highly heated gases to the atmosphere.

It will be understood that instead of forming the clip member 21 separate from the head 25, these parts may be integrally formed or the said head may be provided with tongues corresponding to the tongues 22.

Having thus described the invention, what is claimed as new is:

1. In a fuse plug, a fuse chamber having an opening in one wall thereof, a fuse element removably inserted through the opening and having a contact head, and means interposed between the contact head and the said wall of the chamber for sealing the space around said opening.

2. In a fuse plug, a fuse chamber having an opening in one wall thereof, a fuse element removably inserted through the open ing and having a contact head located exteriorly of said wall, and a' compressible sealing washer interposed between the said contact head. and the said wall of the chamber and surrounding said opening.

3. In a fuse plug, a fuse chamber having an opening in one wall thereof, a fusible element comprising a portion removably inserted through the opening and having a terminal contact head located exteriorly of the said wall, means associated with the head and coacting with the said wall for locking the element against removal, and a compressible sealing washer interposed between the said head and the said wall.

4. As a new article of manufacture, a fuse plug fusible element comprising a length of fusible material formed to provide a locking tongue portion, a clip assembled with the said element and having a tongue portion connected with the tongue portion of the element, and a contact head binding the parts together. I

5. As a new article of manufacture, a fuse plug fusible element comprising a length of fusible material formed to provide a head portion, a shank portion, and a tongue portion located opposite the shank portion, a

clip comprising a head embracing the head portion of the fusible member, and a contact head inclosing and binding together the last mentioned head and the head portion of the fusible element, the said clip having a looking tongue extending therefrom.

6. As a new article of manufacture, a fuse plug fusible element comprising a length of fusible material formed to provide a head portion, a shank portion, and a tongue portion located opposite the shank portion, a clip comprising a headembracing the head portion of the fusible member, and a contact head inclosing and binding together the last mentioned head and the head portion of the fusible element, the said clip having a locking tongue extending therefrom and united to the tongue of the fusible element.

In testimony whereof I afiix my signature.

JOHN G. CLEMENS. [n s.] 

